Garden Notes: Last call for pruning spring-flowering shrubs

And please help your neighborhood turtle.

Shed-size multiflora rose. —Susan Safford

In the time of the solstice we experience the most light, the most visible growth, the most light-driven activity of our natural year. The primary energy has been ultraviolet. From here on out, for the rest of the year, the light is changing, diminishing, and becoming more covert. Then, the longer infrared wavelength of solar energy takes over; it penetrates the earth and works less obviously, commanding plants (and probably all living organisms) to shift to another modus operandi. It warms soils and promotes root growth.

Right now is a sort of last call to prune those spring-flowering shrubs and pinch perennials. The changing light instructs them to start preparing their cells for different operations. Spring-flowering shrubs, those that bloom on “old wood,” begin to form next year’s embryonic flowerbuds. Herbaceous perennials start to harden from green growth into flowering growth.

However, in the case of herbaceous perennials, and many annuals as well, there is leeway. The growth points can be pinched, which will stave off but not prevent flowering, and will activate secondary buds. The result will be bushier, later-blooming plants that need less or no staking: e.g., phlox, asters, perovskia, chrysanthemums, snapdragons, even dahlias. The pinching can only be done optimally for a certain length of time before it sacrifices flowers, just as pruning forsythia can only be done for a certain length of time before next year’s bloom is affected.



The Island of Martha’s Vineyard has had a little bit of everything in 2017, including scant wintriness until harsh spring, lots of rain, high winds, a short and dry heat wave, and chilly days under bluebird skies.

The effect of late-season frost is worth seeing, despite late May and early June’s being the idyllic season of roses and peonies, because it demonstrates that our maritime climate is mercurial and capable of extremes.

We work at a property nearby to Wintucket, and delayed planting summer annuals until the day before the owners’ June arrival. Who wants to sacrifice hundreds of dollars’ worth of plants to the capriciousness of the weather?

This frostbottom vegetation and habitat are identified as being unique and of special interest because they represent the survival of plants that have adapted to those stringent conditions. These formerly disparaged scrublands are composed of “scrub oaks,” actually among the oldest living organisms on the Vineyard. Likewise, the frostbottom ecology is composed of the bird and insect life that has co-selected itself to survive the rare habitat.

The Wintucket frostbottom, frosted. —Susan Safford

Island institutions, such as Felix Neck Wildlife Sanctuary, Polly Hill Arboretum, Sheriff’s Meadow Foundation, Vineyard Conservation Society, and town public libraries supply information and educational materials about the habitats and ecological niches that make the Vineyard unique. David Foster’s recently published “A Meeting of Land and Sea” (Yale University Press) is a wealth of information about Island woodland, including frostbottoms.


Island roadsides

Turtles are venturing across roads now. Please watch for and help them to make it safely across; do not mess with snapping turtles.


Roses of June

June is rose season. The National Garden Bureau has declared this the Year of the Rose, which also happens to be the national flower. Today ruderal areas of the Island are covered in the billowy, mounding plants of Rosa multiflora, and enveloped in their fragrance. Luckily for humans, it is rich and delightful: if it stank it is doubtful whether multiflora rose would have survived as well as it has.

Luckily for birds, and probably many other smaller animals as well, the orange to scarlet hips are an abundant food source that furthers the rose’s aim of securing its future through seed dispersal. The downside for gardeners is their proliferation. Once beyond seedling stage they grow rapidly, with tough, woody roots, difficult to grub out; this rose can take over an area the size of a garden shed while your back is turned.

In the 20th century, when the USDA encouraged farmers to plant windbreaks of Rosa multiflora, an Asian species rose, to inhibit soil erosion, support wildlife, and provide livestock shelter, there was likely no idea of the eventual consequences of the decision: widespread introduction of one of the most prolific of non-native invasive plants. Other roses of June are less problematic. Wild pink Rosa carolina and R. virginiana occur in open, sandy ground, while fragrant Asiatic Rosa rugosa anchors island dunes.

Breeders’ work is paying off for 21st century gardeners, producing plants that are healthier and more easily grown than older roses, native to climates and conditions far different from much of our country. Bailey Nurseries sends garden writers sample plants of new introductions, and sent me several of their Easy Elegance rose series. While it is too soon to report, be on the lookout for these, and similar easy-care rose series from other growers, such as Meidilands, Knockouts, and Drift roses. As long as you have a site with good sun, they are the avenue to satisfaction, without elaborate care requirements.


In the garden

Insect life burgeons now: caterpillars, beetles, pillbugs, earwigs, mosquitoes, spiders, bees and wasps great and small, as well as moths and butterflies. Before going “eeeuuw” when you see them, stop for a minute and think of them as breakfast, lunch, and dinner for so much other life. Certainly birds are dependent upon this banquet for feeding bird babies.

Time to swap out early-spring container plants, such as pansies, and replace with heat-tolerant material for the rest of the summer. Weeds make their appearance big-time with warmer temperatures, especially crabgrass: one weed to pull while it is small.


Polly Hill Arboretum
Karen Perkins will give a talk on epimediums, the “perfect shade perennials,” possessed of a delicate beauty that belies their surprisingly tough nature. She will illustrate the many types commercially available, including some of the exciting new evergreen species from China, on June 24 at 10 am.